Immunocytochemistry/Immunofluorescence: Proteinase 3/Myeloblastin/PRTN3 Antibody [NBP1-25966] - Human PBMC were isolated and adjusted to 106 cells. Cells were fixed with 2% formaldehyde for 10min at 37C. Washed twice with PBS before cytospin the cells onto microscope slides. Cells were blocked with PBS containing 1%BSA for 20min at RT. Excess blocking solution was removed and cells were incubated with Rabbit Ab to c-terminal region of Pr3 (Wegener autoantigen): whole serum for 30min at RT (diluted 1:100 in the blocking buffer). Washed 3X with PBS and incubated with anti-Rabbit Alexa 586 for further 30min. Washed as before and nuclear counterstained with DAPI. Neutrophils and Monocytes, known to have PR3 are intensely stained by the Rabbit Ab to c-terminal region of Pr3 (Wegener autoantigen): whole serum.